From f9eb654fb194e7c404d4984481a18edb9b1c1d7c Mon Sep 17 00:00:00 2001 From: Krishna Chaitanya Chundru Date: Fri, 28 Mar 2025 15:58:31 +0530 Subject: PCI: dwc: Update pci->num_lanes to maximum supported link width If the num-lanes property is not present in the devicetree, update pci->num_lanes with the hardware supported maximum link width using the newly introduced dw_pcie_link_get_max_link_width() API. The API is used to get the Maximum Link Width (MLW) of the controller. Signed-off-by: Krishna Chaitanya Chundru [mani: reworded commit message a bit] Signed-off-by: Manivannan Sadhasivam Reviewed-by: Manivannan Sadhasivam Link: https://patch.msgid.link/20250328-preset_v6-v9-3-22cfa0490518@oss.qualcomm.com --- drivers/pci/controller/dwc/pcie-designware.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'drivers/pci/controller/dwc/pcie-designware.c') diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 97d76d3dc066..cafe91bd9c34 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -781,6 +781,14 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci) } +int dw_pcie_link_get_max_link_width(struct dw_pcie *pci) +{ + u8 cap = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + u32 lnkcap = dw_pcie_readl_dbi(pci, cap + PCI_EXP_LNKCAP); + + return FIELD_GET(PCI_EXP_LNKCAP_MLW, lnkcap); +} + static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes) { u32 lnkcap, lwsc, plc; -- cgit v1.2.3